An antenna 100 illustrated in FIG. 15 is disclosed, the antenna 100 including an unbalanced power supply member having an outer conductor and an inner conductor as with a coaxial cable, and a plate like non-power supply element whose planar shape is molded in an H shape (see Patent Literature 1). As illustrated in FIG. 15, the antenna 100 of Patent Literature 1 includes the unbalanced power supply member 111, a resonance conductor 112, a grounding conductor 113 and a power supply element 114. The resonance conductor 112 is formed with first and second resonance conductors 120a and 120b extending forward in an axial direction of the unbalanced power supply member 111 in parallel to a power supply unit 118. The grounding conductor 113 is formed with a fixing portion 125 electrically connected to the unbalanced power supply member 111, and first and second grounding conductors 126a and 126b extending backward in the axial direction from the first and second resonance conductors 120a and 120b in parallel to a non-power supply unit 119. The power supply element 114 has a predetermined area, extends forward in the axial direction, and is electrically connected to a central conductor 115 of the unbalanced power supply member 111 which constitutes the power supply unit 118.